Method of transmitting control information

Abstract

In a method of transmitting a logical channel by using a downlink transport channel, a plurality of transmission configurations are limited into a limited set of the transmission configurations. Control information relating to the limited set of the transmission configurations of the downlink transport channel is transmitted and at least a part of data of the logical channel is transmitted over the downlink transport channel. Thus, an amount of the control information is reduced.

The invention claimed is: 
     
       1. A method of transmitting a common logical channel over a downlink transport channel having a plurality of transmission configurations, the downlink transport channel being used for transmission of the common logical channel in a 3GPP Long Term Evolution (LTE) network, the method including:
 selecting, from the plurality of the transmission configurations related to the common logical channel of the network operating according to 3GPP Long Term Evolution (LTE), possible transmission configurations of the common logical channel, and not selecting other transmission configurations of the common logical channel; 
 transmitting control information relating to the selected possible transmission configurations of the common logical channel without transmitting the control information relating to the not-selected other transmission configurations which includes at least a modulation scheme; and 
 transmitting a first part of data over the downlink transport channel without transmitting a remaining second part of the data over the downlink transport channel, to reduce the amount of the control information at least relating to the modulation scheme required by a user equipment (UE), 
 wherein the selected possible transmission configurations of the common logical channel are selected in such a way as to remove the need to transmit control information relating to one or more types of transmission configuration. 
 
     
     
       2. A method as claimed in  claim 1  wherein the selected possible transmission configurations of the common logical channel are selected in such a way as to reduce the required amount of control information relating to one or more types of transmission configuration. 
     
     
       3. A method as claimed in  claim 1 , which further includes:
 transmitting the control information corresponding to the common logical channel using out of band signaling without transmitting the remaining control information. 
 
     
     
       4. A method as claimed in  claim 1 , which further includes:
 transmitting the control information corresponding to the common logical channel using in band signaling without transmitting the remaining control information. 
 
     
     
       5. A method as claimed in  claim 3  wherein the transmission of the control information is conducted without the addition of error detection information. 
     
     
       6. A method as claimed in  claim 1 , wherein the selected possible transmission configurations of the common logical channel are selected to eliminate or reduce the need to signal control information which relates, in addition to the modulation scheme, to one or more of the following types of transmission configuration of the downlink transport channel:
 physical resource assignment; 
 Multiple Input Multiple Output antennas transmission (MIMO) information; 
 Hybrid Automatic Repeat ReQuest (HARQ) information; and 
 Payload size information. 
 
     
     
       7. A method as claimed in  claim 1  wherein the communications network operates is an Orthogonal Frequency Division Multiplexing (OFDM) system operating according to the 3GPP Long Term Evolution (LTE). 
     
     
       8. A method as claimed in  claim 7  wherein the common logical channel is any one of a Broadcast Control Channel (BCCH), a (MBMS Control Channel (MCCH), a Multimedia Broadcast and Multicast Service Traffic Channel (MTCCH), and a Paging Control Channel (PCCH). 
     
     
       9. A method as claimed in  claim 7 , wherein the downlink transport channel is a Downlink Shared Channel (DL-SCH). 
     
     
       10. A method as claimed in  claim 7 , which further includes:
 transmitting the control information corresponding to the downlink transport channel and common logical channel on a Physical Downlink Control Channel (PDCCH). 
 
     
     
       11. A method as claimed in  claim 7 , which further includes:
 transmitting the control information corresponding to the selected downlink transport channel and common logical channel on a Broadcast Channel (BCH). 
 
     
     
       12. A method as claimed in  claim 7 , wherein the method includes configuring the downlink transport channel in one or more of the following ways to reduce the amount of control information needed to receive the common logical channel on the downlink transport channel when carrying the common logical channel:
 constraining physical resource assignment of the downlink transport channel; 
 determining the modulation scheme to Quadrature Phase Shift Keying (QPSK); 
 not using Hybrid Automatic Repeat Request (HARQ) in respect of data transmitted over the downlink transport channel; and 
 constraining a possible transport block size. 
 
     
     
       13. A method as claimed in  claim 7 , wherein the possible transmission configurations of the common logical channel are selected such that the only control information necessary to signal the transmission configuration of the common logical channel on the downlink transport channel is the number of resource blocks allocated on the downlink transport channel. 
     
     
       14. A method as claimed in  claim 7 , wherein the transmission of the control information is conducted without the addition of Cyclic Redundancy Check (CRC) error correction bits. 
     
     
       15. A method as claimed in  claim 7 , wherein the common logical channel is a Broadcast Control Channel (BCCH) and the downlink transport channel is a Downlink Shared Channel (DL-SCH) and wherein the part of the common data transmitted on the Downlink Shared Channel (DL-SCH) is a scheduling unit (SU). 
     
     
       16. A method as claimed in  claim 10  which further includes one of:
 signaling the transmission configuration of the Physical Downlink Control Channel (PDCCH) to the user equipment (UE); or 
 predefining the transmission configuration of the Physical Downlink Control Channel (PDCCH). 
 
     
     
       17. A base transceiver station (BTS) for use in a radio communication system of the 3GPP Long Term Evolution (LTE) operation, the base transceiver station (BTS) configured to communicate with a plurality of mobile terminals over a plurality of channels, said base transceiver station (BTS) being configured to transmit at least a portion of the data of the common logical channel over a downlink transport channel using a method as claimed in  claim 1 . 
     
     
       18. A communication system including a BTS as claimed in  claim 17 . 
     
     
       19. A non-transitory computer-readable medium containing thereon a computer program product for use in a BTS to transmit a common logical channel in a communications network of the 3GPP Long Term Evolution (LTE) operation using a downlink transport channel having a plurality of transmission configurations, the computer program, when executed on a computer, causing the computer act as the base transceiver station (BTS) and operate in accordance with the following steps of:
 selecting in the communication network operating according to 3GPP Long Term Evolution (LTE), from the plurality of the transmission configurations, possible transmission configurations of the common logical channel over the downlink transport channel, and not selecting other transmission configurations of the downlink transport channel; 
 transmitting control information relating to the selected possible transmission configurations of the common logical channel without transmitting the control information relating to the not-selected other transmission configurations; and 
 transmitting a first part of the data of the common logical channel over the downlink transport channel without transmitting the remaining data of the common logical channel which includes at least a modulation scheme, to reduce the amount of the control information at least relating to the modulation scheme required by a user equipment (UE). 
 
     
     
       20. A method as claimed in  claim 1 , wherein the method includes configuring the downlink transport channel to reduce the amount of control information needed to receive the common logical channel on the downlink transport channel when carrying the common logical channel by not using Hybrid Automatic Repeat Request (HARQ) in respect of data transmitted over the common logical channel,
 wherein the selected possible transmission configurations of the common logical channel are selected in such a way as to remove the need to transmit control information relating to one or more types of transmission configuration.